[unreadable] The focus of the proposed research is to examine the role of the serotonin type-3 receptor (5-HT3r) in adolescent cocaine facilitated offensive aggression. Cocaine has been observed to differentially effect several neurotransmitter systems and consequently behavioral states subserved by these systems. The serotonin type-3 receptor is affected directly by cocaine and thus may serve as a direct mechanism of action facilitating the behavioral effects of this abused drug. My previous research has localized this stimulatory receptor to several brain areas implicated in aggression control including the anterior hypothalamus, the bed nucleus of the stria terminalis, the medial amygdala and the lateral septum. Evidence, provided by the sponsoring investigator, of decreased serotonergic innervation of these brain areas in aggressive, adolescent cocaine treated animals warrants the investigation of the 5-HT3r's role in this phenomenon. The goals of the experiments outlined in this proposal are 1) to manipulate cocaine-facilitated offensive aggression with pharmacological agents that specifically target the 5-HT3r and 2) to provide a more complete model of the circuitry regulating adolescent cocaine-facilitated aggression by characterizing how and if cocaine exposure affects this receptor. Findings observed in the proposed experiments will provide a better understanding of the aberrant behaviors observed in young adults and the risk factors predisposing the young to violent behavior resulting from experimental cocaine use. [unreadable] [unreadable] [unreadable] [unreadable]